Building my bobtach

[shawn macananny]

Thanks, The parts were all drawn in a cad cam program and cut out on a plasma so the holes were cut out at the same time. Drilling the holes with a mag drill works fine just remember to make the holes bigger to allow for welding warping and movement. That allows for floating the part (bushing).

I was really impressed with the bobtach then i watched your video for your Cummins engine. You are incredible. That's all i can say.

 

[wings5j]

I was really impressed with the bobtach then i watched your video for your Cummins engine. You are incredible. That's all i can say.

Yes, showing the steps in building the Bobtach are great but I too appreciated the link to the engine building project.
On a positive note, I think I will have my wife watch so that she sees how much my shop is really lacking. ;-) I still do all of my cutting with an oxy/acetelyne set-up or bandsaw or chopsaw.
Thanks,
John

 

[renopker]

Yes, showing the steps in building the Bobtach are great but I too appreciated the link to the engine building project.
On a positive note, I think I will have my wife watch so that she sees how much my shop is really lacking. ;-) I still do all of my cutting with an oxy/acetelyne set-up or bandsaw or chopsaw.
Thanks,
John

Nothing wrong with a torch grinder,chop saw and saws-all ,been there done that. Heres todays progress # is of the bored tube in place & welded,

 

[renopker]

Nothing wrong with a torch grinder,chop saw and saws-all ,been there done that. Heres todays progress # is of the bored tube in place & welded,

Cutting the tube out with the saws-all

 

[renopker]

Cutting the tube out with the saws-all

 

[Tazza]

Nice job, the way i did mine was slightly different. I had to cut those bosses out as they were really worn. I made new ones and installed everything including the pins in the arms, the pins held the bosses straight, i then welded the bosses into place. The pins did a good job holding the bosses straight. They did move a little bit when i took the bobtach off and welded around the ends to give it a good join. Taking a little off the bushings fixed the small amount of binding it had. I think i left my tollerences too tight in the first place, not allowing quite enough clearance for the grease, i think it was only .005 to .008"

 

[renopker]

Nice job, the way i did mine was slightly different. I had to cut those bosses out as they were really worn. I made new ones and installed everything including the pins in the arms, the pins held the bosses straight, i then welded the bosses into place. The pins did a good job holding the bosses straight. They did move a little bit when i took the bobtach off and welded around the ends to give it a good join. Taking a little off the bushings fixed the small amount of binding it had. I think i left my tollerences too tight in the first place, not allowing quite enough clearance for the grease, i think it was only .005 to .008"

So you used the arms as your fixture, no set rule I like the long bar on short bushings. The interesting thing is when I cut through there was no binding and no movement I was a pleasantly surprised as well.

 

[Tazza]

So you used the arms as your fixture, no set rule I like the long bar on short bushings. The interesting thing is when I cut through there was no binding and no movement I was a pleasantly surprised as well.

Yeah, i found it did work pretty well, but if i was able to do a full length like yours, i can see it holding up a little better as it would have held while i did my final welds that made it twist slightly.
Its a great feeling when you put things together after a big weld and they still line up as they should. Too often they move just a little too much.

 

[renopker]

Yeah, i found it did work pretty well, but if i was able to do a full length like yours, i can see it holding up a little better as it would have held while i did my final welds that made it twist slightly.
Its a great feeling when you put things together after a big weld and they still line up as they should. Too often they move just a little too much.

Finished the bobtach today It will be sand blasted and powder coated as soon as I get the cylinders modified, still need heat treat the wedge pins as well.

 

[Tazza]

Finished the bobtach today It will be sand blasted and powder coated as soon as I get the cylinders modified, still need heat treat the wedge pins as well.

I like your table. Sure would save the back on a lot of jobs.

 

[renopker]

I like your table. Sure would save the back on a lot of jobs.

Back from powder coat

 

[Tazza]

Back from powder coat

OOOOOOOH so shiny when it it going to be mounted to the machine? i want to see it in action!

 

[6brnorma]

OOOOOOOH so shiny when it it going to be mounted to the machine? i want to see it in action!

That is outstanding work. Doubt I'll live long enough to become that accomplished.

 

[skidsteer.ca]

That is outstanding work. Doubt I'll live long enough to become that accomplished.

I'd like to hang out with you in your spare time, great job!
Ken

 

[renopker]

I'd like to hang out with you in your spare time, great job!
Ken

Thanks all .